Synthesia or HeyGen vs. 3D Animation AI: Avatars or Real 3D for Technical Products?

Key points

• Pick by what viewers need to see. Synthesia and HeyGen put avatars, slides, and motion graphics on screen, while real 3D shows the shape of your product and the moving parts inside it.
• Choose an avatar tool for training libraries, many languages, SCORM, quizzes, or a presenter. 3DCG Video AI has none of those, so it's the wrong tool for that job.
• Choose real 3D to show how a machine works. As of November 7, 2026, neither Synthesia's nor HeyGen's pricing page mentions 3D scenes or CAD import.
• Avatar minutes cost far less. Synthesia's plans work out to about $1.50–$1.60 per minute at the full allowance, against about $35 for a Standard minute here (published estimates, as of November 2026). Quality limits and included work differ.
• You can use both: build the training in an avatar tool and drop in a 3D MP4 for the part no camera can show.

What each one offers (checked November 7, 2026)

We checked these facts on each company's own site. Prices are published estimates (as of November 2026), and they can change.

Item	Synthesia	HeyGen	3DCG Video AI
What viewers see	AI avatars, motion graphics, voiceover, music, and B-roll (synthesia.io)	Your slides, unchanged, with an optional avatar in a corner circle (heygen.com), or scenes with B-roll from a PDF (heygen.com)	3D scenes of the product, diagrams, charts, and camera moves, with AI narration and captions. No presenter
What you can attach	PowerPoint, PDF, Word, text, or a URL (help.synthesia.io)	PowerPoint or PDF (heygen.com)	PDF, Word, PowerPoint, Excel, images, text files, CAD 3D (STEP, IGES, STL, OBJ, PLY, glTF/GLB, 3MF), and drawings (DXF recommended, DWG)
Languages	140+ languages and voices (synthesia.io)	175+ languages and dialects on paid plans (heygen.com)	No translation or dubbing feature
Training features	Quizzes and branching. SCORM export is listed on the Enterprise plan (synthesia.io)	SCORM export and LMS integrations on Business (heygen.com)	No SCORM and no quizzes
Certifications listed	ISO 42001, plus a SOC 2 badge (synthesia.io)	SOC 2 Type II (heygen.com)	No third-party security certification
Published price	Starter: $19 a month, up to about 12 minutes. Pro: $89 a month, up to about 60 minutes (synthesia.io)	Creator: $29 a month. Pro: from $49 a month. Business: $149 a month, plus $20 per added seat (heygen.com)	No subscription. Packs from $5 to $300. 1-minute Standard with two small revisions: about 3,500 credits ($35). High Quality: about 7,000–12,000 credits ($70–$120). See Pricing

Colossyan is another avatar tool aimed at training. It lists SCORM export on its Professional plan, along with branching, assessments, and more than 100 languages (colossyan.com).

What the price gap means

At the plan limits above, a full Synthesia allowance comes to about $1.50–$1.60 per minute. Its newer agent, Syren, is priced differently: Synthesia says a 1-minute video typically uses 1,000–2,000 credits (synthesia.io), which is about $15–$30 at those plan rates by our arithmetic. A Standard minute here is about $35.

These are different products, so quality limits and included work differ. An avatar minute reuses a presenter and layouts, and a 3D minute builds new scenes. If you need a library of 50 policy videos, an avatar tool is the sensible purchase.

Same spec sheet, different video

Say you hand over a spec sheet and slides for a centrifugal pump. This describes the two methods. We did not make both versions.

Item	Avatars and slides	Real 3D
On screen	Your performance table and diagrams. HeyGen's PowerPoint tool keeps layout and charts but drops PowerPoint's own animations (heygen.com)	As in the pump sample, the impeller flings water outward, and the widening casing turns speed into pressure
Strong at	Dense tables and exact figures, read aloud	Internal motion, how parts sit together, the order of operations
Time	Minutes, by HeyGen's account (heygen.com)	For 1 minute of Standard: storyboard in a few minutes, build in 30–60 minutes, export in about an hour, plus your review

Avatar tools can add generated footage too. Synthesia's editor can make short clips with third-party models such as Veo 3.1 and Gemini Omni (help.synthesia.io). Those clips are generated, so they carry the limits described in Can AI make an accurate product video?

When an avatar tool is the right call

• You need many training videos. Talking through a procedure doesn't need 3D, and the cost per video stays low.
• You publish in many languages. 3DCG Video AI has no translation or dubbing.
• Your LMS needs tracking. SCORM, quizzes, and branching live on the avatar side.
• You want a face on screen. 3DCG Video AI has no avatars or presenters.
• Procurement requires certification. 3DCG Video AI has no third-party security certification.

When real 3D is the right call

• You need a mechanical animation of something no camera can reach. The DR-5 power driver sample walks through its motor, planetary gears, and clutch. It's a fictional product.
• The shape is the point. You can attach CAD files and use those shapes. CAD exports from real CAD software have not been tested yet, and no current sample was built from a customer's CAD file.
• You're starting from a spec sheet or a deck. See turning a spec sheet, PDF, or PowerPoint into a 3D explainer video.
• You need a few videos, not a library. The price gap adds up with volume.

You get a 1080p MP4 with no 4K and no 3D source files, and you need no 3D or editing skills to make it.

Using both

Build the course in an avatar tool and use 3D only for the part slides can't explain. Synthesia accepts uploaded MP4 files up to 250 MB (help.synthesia.io), and HeyGen's PDF tool says you can add your own clips (heygen.com). A 78-second export from 3DCG Video AI measured 19 MB, so file size isn't an obstacle. A short segment won't cost proportionally less, though: a 15-second Standard video with two revisions measured about the same as the 1-minute guide.

Frequently asked questions

Should I use 3D if I only want my PowerPoint turned into a video?

No. A slide or avatar tool is faster and cheaper for that. 3DCG Video AI uses your deck as source material and builds new scenes, so it won't show your slides as they are.

Do these tools train AI on my documents?

It varies. Synthesia says it doesn't use customer data to pre-train its AI components (synthesia.io). HeyGen excludes Enterprise data by default and lets other users opt out by contacting it (heygen.com). With 3DCG Video AI, attached documents are not used for AI training, and documents and outputs are deleted after 30 days.

Can 3DCG Video AI explain things other than machines?

Yes. The financial statements sample shows how three reports connect, with no machine in it. If the content is mostly talking points, though, an avatar or slide tool is the better value.